Impeller



FIG. 1 is a top front perspective view of an impeller showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof; and,

FIG. 7 is a rear view thereof.

The broken lines shown in FIG. 4 are for the purpose of illustrating portions of the article that form no part of the claimed design. 

CLAIM The ornamental design for an impeller, as shown and described. 